"It's portraying a guy who just passed away that is really fresh in people's minds, that people are really passionate about, and care about, and have an opinion about - that's really scary," Kutcher said.

"Especially portraying a guy that I really admire... it's terrifying."

The movie's release had been postponed from April 19 - the anniversary of the first Apple computer - and will now be released in the US on August 16.